Die-cushion



D. STRAND.

A mE cusmon.

APPLICATION FILED MAY l, I9L8..

1,354,785. Patented on. 5,1920. l SHEET l.

6 SHERTS- m Il D. STRAND.

DIE cusHloN.

APPLICATION FILED MAY 7, 191.8- A 1,354,785. Patented Oct. 5,1920..

y 6 SHEETS-SHEET 2.

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n, SIRAND. DIE CUSHION.

APPLICATION FILED MAY 7, 1916.

Patenwd Oct. 5, 1920.

QW. www@ Q/ M M m Patented Oct. 5, 1920.

6 SHEETS-SHEET 4.

Inde/tor D. STRAND.

DIE CUSHION.

APPLICATION FILED MAY Z, I9I.8. 1,354,785.

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DIECUSHION.

APPLICATION FILED MAY7, 1918. l

Patented Oct. 5, 1920.

6 SHEETS-SHEET 5.

D. STRAND.

DIE CUSHION.

^ APPLICATIQN man MH, 1918.

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DAVID STRAND, or CHICAGO, ILLINOIS, AssICNo'R, BY MESNE ASSIGNMENTS, To

' RUDOLPH W. CLASNER, or CHICAGO, ILLINOIS.,

DIE-CUSHION.

in die cushions of the fluid pressure type adapted to be secured to ,adie press, wherebytlie same may be readlly attached to or detached fromthe machine as a Single 1 1n1t, and one ofthe objects of the invent1on1s to provide an improved self-contained unitary device of thischaracter embodying means constituting` a self-pumping mechanism fosupplying uid to the cushion.`

A further object is to provide an improved device of this characterwhich will be simple, durable, and compact .1n constructionand eectiveandefiicient 1n operation.

To the accomplishment of these ends, and the equipment of other new anduseful obiects as will appear, the invention consists in the features ofnovelty .in substantially the construction, combination, and arrangementof the several parts hereinafter more fully described and claimedand'shown 1n the accompanying drawings, in which:-

Figure 1' is a vertical sectional view of a portion of a die presshaving a cushion attached thereto constructed in accordance with theprinciples of this invention.

Fig. 2 vis a viewA similar to' Fig. 10fanother form.

Fig. 3 is a similar view of another-form of the invention.

Fig. 4 is a similar view o f yanother form of the invention.

Fig. 5 is a similar viewv of another form of the invention. v, l,

Fig. 6 is a similar view of still another form of the invention.

Referring more particularly `to the drawings, the numeral l10 designatesgenerally a bolster plate of a die press having mounted thereon a dieLholding plate 11, in which is arranged a cutting vdie 12'whichencompasses a forming block 13.' A pressure ring 14 is preferablydisposed between the vforming block and the cutting die 12, whichcooperates lwith a cutting `die 15, the latter being mounted upon areciprocating mem- Specication of Letters Patent. v

Application led May 7, 1918. 'Serial N0. 233,084.

- Patented Oct. 5, 1920.

ber or structure 16, as heretofore known in machines 'of this character.Y

Connected with the machine in a manner to coperate with the pressurering 14 is a uidpressure cushion` which preferably comprises twocylinder members 16, 17 having their respective outer ends 18, 19 closedwith the adjacentends open and telesco'ping with each other, so as toform a chamber or. recep`tacle within the cushion and vin which chamberof the receptacle a lubricant 20 is adapted-to be held. The'element 17of .the cushion preferably serves in the capacity of a lpistonelementgfnd may be constructed 1n any desirable or suitable manner, butpreferably comprises a section 2l which telescopes with the'elements 17and the two are held; together in any desired Aor suitable manner, suchas by means of fastening devices 23 in the form vof screws which/passloosely through the closed end 19 of the element 17, and then haveengagement with the element 21 so Ithat the parts maybe relativelyadjusted. The open'end of the element 21 is preferably shaped to form aseat 23 which extends circumferentially ofthe element 21; and the freeend 24 of the element 17 terminates short of the seat 23 so as to form aspace for packing material 25 arrangedk therein, and which packingmaterial is adapted to contact with the vinner face of the wall of theelement 16.

It will be manifest that with this construction, and when the lubricant'20 isheld within the cushion, and when a reciprocating or relativemovement is imparted to the] members ofthe cushion, the packing will bemoved into' and out of the lubricant 20, and when-it is desired, thelelements 17 21 may be adjusted relatively to each other so as to forcethepacking against the wall of the element 16. K

. The cushion thus formed lis adapted` to be secured t'ojthe machine inlany desired or suitable manner,- preferably by means of tie rods26whichv have engagement at one end with the closed end 18 of the element16 and are'connected by their other ends with an annular member 27'preferably ,provided with a shoulder 28 adapted to engage and rest uponthe upper edge of the element 16.

The ring or element 27 is connected with a stationary portion of themachine, by means is depressed, the element 17 of the cushion willalso'be depressed to cause a compression within the cylinder, and thisis accom- -plishedthrough the medium of the pins 31 and plate disposedbetween the pressure rin 14 and the end of the element 17.

ir is supplied to the cushion in any desired or suitable manner,preferably by means of a pumping apparatus which, in the form'of theinvention shown in Figs. l and 2, comprise a stationary piston element32 which is secured to any fixed portion of the cushion, preferably theend 18 of the element 16 by means of suitable fastening devices 33, anda cylinder element 34, pref; erably arranged within the cushion, isconnected with the movable element 17 in any suitable manner such as bymeans of the fastening screws 22, so that when the ele# ments 17, 16 aremoved relatively with relation toy each other, the cylinder element 34will pass over the piston element 32 and any air which has been drawninto the cylinder 34 will be forced therefrom through the valvedcontrolled outlet 35 into the cushion. The supply of air for the pumpmechanism is drawn from the atmosphere through a suitable inlet opening36 controlled by a valve 37 and a packing box 38 is provided between thecylinder 34 and piston element 32, as will be understood.

The pressure within the cylinder is maintained substantiallyl constantand this is accomplished by means of a suitable outlet 39 which extendspreferably through the closed end 18 of the element 16 and terminates ata'point above the level of the lubricant 20 therein. Connected with thisoutlet 39 is a valve 40 adapted to be actuated under an abnormalpressure, and which valve may be of any desirable or suitableconstruction adapted tobe set so as to maintain a predeterminedpressure, but when the pressure is excessive, the valve will yield andthe air or fluid will pass therefrom into the atmosphere. A pressuregage 41 may be provided, which is connected with the valve 40, and bymeans of which pressure gage the predetermined pressure may bedetermmed.

In the form of the invention shown in Fig. 1, a plurality of pumpdevices are shown as being arranged Within the cushion, but in the'formof the invention shown in Fig. 2, a single pump apparatus is disclosed,

and in this form of the invetion the pressure within the cushion ismaintained substantially constant by means of a suitable compressed airtank 42 which lhas communication with the interior of the cushion bymeans of a, pipe 43, so that as the cushion is operated and as thepressure iscreated, the

Huid will flow freely into and out of the' cushion and out of and" intothe tank 42.

In the vform of the invention' shown in Fig. 3, the pump devices aredisposed exterior of the cushion and have connection with the cushionthrough the medium of suitably connecting pipes 44, and whichconnections are controlled by a -valve 45, the free end 46 of theconnecting pipes 44 extend into the cushion and terminate ata pointabove the level of the lubricant 20 therein.

In the form of the invention shown in Fig. 4, the pumping apparatusconsists essentially of a cylinder element 47, which is preferablyarranged interior of the cushion and has an opening 48 through theclosed end` 18 of the element 16. The closed end 49 of the cylinder 47is provided with an opening 50 controlled by a valve 51 and a piston 52having a valve opening 53, which is arranged to reciprocate within thecylinder 47. This piston 52 is provided witha piston rod 54 surroundingwhich isv an adjustable collar collar 55 is threaded and the barormember 59 is itself supported, preferably by means of a suitablenumber of bars 60 which have an adjustable connection withthe bar 59,preferably by passing loosely therethrough and which are held inposition by means of suitable fastening devices 61, such as screws orthe like. The other ends of the bars 60 are preferably detachablyconnected with the pin plate 30.

With this improved construction it will be manifest that when thepressure ring 14 is operated toI depress the pin plate 30, thelatterwill, through the medium of the bars 60 and 59 move the piston 52in the cylinder 46 and this will cause air to pass through the valvedopening 53 into thespace between 'the end 49 of theF cylinder 47 and thepiston 52, to be dischaiged therefrom through the opening 50 into thecushion to be compressed therein. The pressure maybe maintainedsubstantially constant in the cushion, in this form of the device, inany suitable manner,

it will be manifest that by adjusting the. same with respect to the bar59, the relative movement of 'the piston 52 with respect to the cylinder47 may be 'varied while the stroke orrelative movement-of the cushionelements will re ain constant and by this means, it will b lmanifestthat the pressure may be varied. x

It is thought that the operation of this improved apparatus will beclearly understood from the above description, but briefly stated it isas follows:

. Assuming that a metal sheet has been placed on the part 12, thememberr16 and.

its associated 'elements descend, the coperating cutting dies 15 and 12acting to cut out a blank of the proper size and shape,

the die 15 entering the die 12, as will be. readily understood. As itdoes s0, the mar- 5 ginal portion lof the blank will be gripped orclamped between the pressure ring 14 and the lower face of the punch ordie 15. During the continued descent of the part 16, thev pressure ring14, which is. forced downwardly by it, is pressed upwardly, securelyclamping the sheet metal blank by reason of the action of the compressedair in-the cushion acting 'against the moving member 17 of the cushion,it being understood that the pressure, of course, is to be regulatedeither by the valve 40 when used or the compressed air tank 42 when thatform is used.

The downward, movement of the pressure ring 14, of course, causes arelative movement of the cushion elements, one with relation to theother, and a portion of the air within the cushion,` will be forced outof the outlet 39, when the pressure exceeds the predetermined pressureto which the valve 40 is set; and this, it will be manifest, willmaintain the pressure substantially constant within the cushion.

The pressure around the ring, that is, around the forming block 13, isalso sub.- stantially uniform. In thus pressing the sheet downwardly itis formed or drawn into shape around the fixed forming block 13, theco-acting descending part 15 and 14 during this operation, clamping theedge of the blank sufficiently to prevent its wrinkling or folding, butnot sufficient, however, to 'cause the article being formed to tear orbecome severed. It will also be obvious that, during the relativemovement of the elements 16, 17 of the cushion, air will be pumped intothe cushion by means of the pumping apparatus. It is sometimesdesirable, to slightly release the gripping movement of the pressureadvance of the forming operation, so as to permit the blank to slipslightly. This may be accomplished in any desirable or suitablemanner,but preferably by means of arms or bars 63 which latter are preferablyconcommences to enter thekdie 12, and when thev element 16 'engages theends of these elements 63, theelement 17 of the cushion will be slightlydepressed, allowing the pressure rin llease the blank.v An adjustingdevice 65 'may be connected with the'ends of the bars or members 63 forregulating the time at which this releasing movement will take place.These adjusting devices 65 may be in the form of nuts 0r collars screwedupon the threaded extremity 66 of the bars 63 and held in their adjustedpositions by means of nuts or collars 67. l

If desired, a portion of the air within the cleaning or blowing offarticles from the pressure ring 14 or the ie 12, and to that end theremay be provided a nozzle 68, with which is connected a tube or pipe 69,the free end of which extendsinto the cushion and terminates as at 70 ata point above the level of'the lubricant therein, so that when theelement 17 is forced into the element 16 of the cushion, a portion ofthe air will be forced throughthe pipe 69 to be discharged through thenozzle 68 against the work, and which nozzle may be supported by asuitable bracket 71 supported to a fixed portion of the machine. A

While the preferred forms of the invention have been herein shown anddescribed, it is obvious-that various changes may be made in the detailsof construction and in the combination and arrangement of the severalparts, within the sco o ,f the claims Vwithout departing from the spiri+of this ing on said blank, gripping means during such relative movementof vsaid gripping means and block, said' cushion embodying relativelymovable opposed coperating cylindrical elements, each element having anopen and a closed end, the open ends of the elements telescoping, one-ofsaid lele- 14 to recede slightly and thereby recushion may be employedas a means for" ments being fixed and the other of said elements beingoperatively related to the said gripping means, said cushion alsoembodying means whereby the relative movement of the. cushion elementswill supply fluid between the said elements.

2. The combination of a forming block, means adapted to grip a sheetmetal blank, means to move said gripping means and block relatively onewith relation to the other to cause the shaping of the blank over theblock, and a fluid pressure cushion acting on said blank-gripping meansduring such relative movement of said gripping means and block, saidcushion embodying relatively movable opposed cooperating cylindricalelements, each element having an open and a closed end, the open ends ofthe elements telescoping, one of said elements being fixed, the other ofthe said elements "being responsive in its operation to the operation ofthe said gripping means, and provisions whereby fluid will be suppliedto the cushion by the relative movement of the said elements.

3. The combination of a forming block, means adapted to nfrip a sheetmetal blank, means to move said gripping means and -block relatively onewith relation to the other to causethe shaping of the blank over theblock, and a fluid pressure cushion acting on'said blank gripping meansduring such relative movement of said gripping means and block, saidcushion being freely detachable and self-contained and embodyingrelatively movable opposed coperating cylindrical elements having opentelescoping ends, one of said elements being fixed, the other of saidelements being responsive in its operation tothe operation of saidgripping means, and provisions whereby Huid will be supplied between theelements by the relative movement of the said elements. l

4. The combination of a forming block,

means adapted to grip a sheet metal blank,

means to move said gripping means and block. relatively one withrelation to the other to cause the shaping of the blank over the block,and a fluid pressure cushion acting on said blank gripping means andblock, said cushion being freely detachable and self-contained andembodying relatively movable opposed coperating cylindrical elementshaving open telescoping ends, one of said elements being fixed, theother of said elements being responsive in its operation to theoperation of the said gripping means, provisions whereby fluid will besupplied between the .elements by the relative movement4 of the saidelements, and

means whereby the pressure within the cushz ion will be automaticallycontrolled.

5; The combination of a forming block, means adapted to grip a sheetmetal blank,

means to move said gripping means and block relatively, one withrelation to the other to cause the shaping of the blank over the block,and a self-contained and freely detachable fluid pressure cushion actingon said blank gripping means during such relative movement of' saidgripping means and block, said cushion embodying opposed cylindricalelements having open telescoping ends, one of said elements being fixed,the other element being operatively related to the said gripping means,one of said elements forming an oil chamber into which the other elementtelescopes, means whereby the relative movement of the'cushion elementswill supply fluid between the cushion elements, there being an outletfor the fluid leading from between the elements, and means forcontrolling said outlet.

6. The combination of a forming block, means adapted to grip a sheet`metal blank, means to move said gripping means and block relatively onewith relation to the other to cause the shaping of the blank over theblock, and a fluid pressure cushion acting on said blank gripping meansduring such relative movement of said gripping means and block, saidcushion embodying relatively movable opposed coperating cylindricalelements, each element having an open and a closed end, the open ends ofthe elements telescoping, one of said elements being fixed and the otherof said elements being operatively related to the said gripping means,said cushion 'also embodying means whereby the relative movement of thecushion elementsy will supply fluid between the said elementsthe lastrecited means embodying a pump structure carried with the said cushion.

7. A self-contained freely vattachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable cylindrical elements having their outer en ds closedand their inner ends open and telescoping, means for anchoring one ofthe said elements, one of the elements constituting an oil chamber intoand out of which oil the other elements move, meanswhereby the relativemovement of the said elements will supply fiuid to be compressed betweenthe said elements, there being an outlet for the fluid leading frombetween the elements above the level of the oil in the cushion.

8. A self-contained freely attachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable cylinder elements havingl their outer endsclosed'an'd theirinner ends open and telescoping, means for anchoringone of the said elements, one of the elements constituting an oilchamber into and out of which oil the other element moves, means wherebythe relative moveto be compressed between the saidv elements,

and means for maintaining a substantially unvarying pressure in thecushionpfbetween said elements. l

9. A self-contained freely attachable and detachable-fluid pressurecushion for sheet metal die machines, said Cushion embodying opposedrelatively movable cylinder elements having closed outer ends and opentelescoping inner ends, means for anchoring one of the said elements, apump structure carried with' the cushion and adapted to supply fluid' tothe cushion by the relative movement of the' said elements, and meansfor maintaining a predetermined pressure in the cushion.

10. A self-contained freely attachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable cylinder elements, having closed outer and' opentelescoping inner ends, means for anchoring one of the said elements,means whereby 4the relative movement of said elements will supply fluidto the cushion to be compressedA therein, means for maintaining apredetermined pressure in the cushion, one of said elements Iembodyingtelescoping sections, one of the sections having a packing seat, packingbetween the saidsections and engaging said seat, and means adjustablysecuring the said sections together for holding and compressing saidpacking, said packing forming a fluid tightl joint between the cushionelements.

11. A self-contained freely attachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable telescoping cylinder elements having closed outerends, means 'for anchoring one` of the elements, said means embodying atubular element secured to the end of one of the cushion elements andpassing through the other cushion element and upon which the latterslides,-

a fastening device passing through the tubular element, one end of thefastening device Vextendingbeyond one end of the tubular element, saidfastening device having a shoulden engaging the other end of the tubularelement, and means whereby the relative movement of the cushion elementswill supply fluid to the cushion to'be compressed detachable fluidpressure cushion for sheet metal die machines, said cushion embodyingopposed relatively movable telescoping cylinder elements having closedouter ends, means for anchoring one of the elements,

said means embodying mechanism secured to one of the cushion-elementsand anchored to afiXed part of the machine, means whereby the relativemovement of the cushion elements will supply fluid to the cushion to beVcompressed between the cushion elements, one of the cushionv elementsforming a lubricant receiver, there being an outlet leading from thecushion from above the lubricant, and means for controlling said outlet.

13. A self-contained freely attachable and detachable fluid pressurecushion forsheet metal die machines, said cushion embodying opposedrelatively movable cylinder elements having closed outer ends and opentelescoping inner ends, means for anchoring one, of the said elements, apump structure carried with the cushion and adapted to supply fluid tothe cushion by the relative movement of the said elements, and means formaintaining a predetermined pressure in the cushion, said pump structurebeing located within the cushion and being disposed between the saidcushion elements.

14. A self-contained freely attachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable cylinder elements having closed outer ends and opentelescoping inner ends, means for anchoring one of the said elements, apump structure carried with the cushion and adapted to supply fluid tothe cushion by the relative movement of the saidy elements, means formaintaining a predetermined pressurein the cushion, said pump structureembodying a cylinder and piston, said pump cylinder being connected withone of the cushion elements and said piston being connected with theother cylinder element whereby the relative movement of the cylinderelements will actu'ate the pump.

15. A sheet metal press embodying a forming block, means adapted to gripa sheet metal blank, means to move said gripping means and bloc'krelatively to one another to cause the shaping of the blank over theblock, inl combination with a freely attachable and detachable fluidpressure cushion acting on said blank gripping means with substantiallyunvarying pressure during such relative movement of said gripping meansand block, and means operating automatically to slightly relieve thepressure of ^the said gripping means upon the blank at a predeterminedpoint in the shaping of the blank.

16.' A sheet metal press embodying a forming block, means adapted togrip a sheet metal blank, means to move said gripping means and blockrelatively to one anotherto cause the shaping of the blank over theblock, in combination with a freely attachable and detachable fluidpressure cushion acting on said blank gripping means with substantiallyunvarying pressure during such relative movement of said gripping -meansand block, and means operating automatically to slightly relieve thepressure of the said gripping means upon the blank at a predeterminedpoint in the shaping of the blank, the said pressure relieving meansbeing operatively related to the said cushion.

17. A sheet metal. press embodying. a forming block, means adapted togrip a sheet metal blank, means to movel said gripping means and blockrelatively to one another t'o cause the shaping of the blank over theblock, in combination with a freely attachable and detachable fluidpressure cushion acting on said blank gripping means with substantiallyunvarying pressure during such relativevmovement of said gripping meansand block, means operating automatically to slightly relieve thepressure of the said gripping means upon the blank at a predeterminedpoint in the shaping of the blank, and means whereby the time ofoperation of the said pressure relieving means may be varied at will.

18. A sheet metal press embodying a forming block, means adapted to gripa sheet metal blank, means to move said gripping means and blockrelatively to4 one another to cause the shapingof the blank over theblock, in combination with a freely attachable and detachable fluid.pressure cushion acting on said blank gripping means with substantiallyunvarying pressure, during such relative movement of said gripping meansand block, means whereby a portion of the fluid will be discharged fromthe cushion during such relative movement, and means for discharging ablast of fluid from the cushion adjacent the forming block.

19. A self-contained freely attachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable cylinder elements having closed outer ends and opentelescoping inner ends, means for anchoring one of the said elements, apump structure carried with the cushion and adapted to supply fluid tothe cushion by the relative movement of said elements, and a compressedfluid tank having communication with the cylinder, whereby the pressurein the cushion land tank is always maintained substantially the same. y

420. A self-contained freely attachable and detachable fluid pressurecushion forsheet metal die machines, said cushion embodying opposedrelatively movable cylinder elements having closed outer ends andopentelescoping inner ends, means for anchoring one of said elements,and a pump structure adapted to supply fluid to the cushion, said pumpbeing operableby the relative moveinents having closed outer ends andopen telescoping inner ends, means for anchoring one of said elements, apump mechanism responsive in its operation to the relative movement ofthe cushion elements, said pump mechanism operating to supply iiuid tothe cushion, and means operating automatically to maintain asubstantially unvaryi'lg pressure in the cushion.

22. self-contained freely attachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable 4cylinder elements having closed outer and opentelescoping inner ends, means for anchoring one of said elements, andpump mechanism responsive in its operation to the relative movement ofthe cushion elements, and adapted to supply fluid to the cushion.betweenA the elements thereof, said pump mechanism receiving its vsupplyof fluid from the atmosphere.

23. A self-contained freely attachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable cylinder elements having closed outer and opentelescoping innerl ends, means for anchoring one of said elements, andpump mechanism responsive in its operation to the relative movement ofthe cushion elements, adapted to supply Huid to the4 cushion between theelements thereof, said pump mechanism receiving its supply of fluidfromthe atmosphere, and means operating to automatically maintain asubstantially unvarying pressure in the cushion.

24. The combination of 'a sheet metal shaping member, means coperatingwith said member for shaping thematerial and embodying gripping meansfor the material, a freely-detachable and self-contained fluid pressuremeans for maintaining a substantiallyunyarying pressure on the grippingmeans during the operation of shaping the material, said iiuid pressuremeans embodying a piston and a .cylinder element, means whereby thegripping means will be responsive in its operation'to the operation ofone of the parts of the cushion, and means embodying pump mechanismresponsive in its4 115 operation to the relative movement of the cushionelements forl supplying fluid between the cushion elements.

25. The combination of a sheet metal shaping member, means coperatingwith said member for shaping the material and embodying gripping meansfor the material,

a freely detachable and self-contained fluid pressure means formaintaining a substantially unvarying pressure on the gripping meansduring the operation of 'shaping the material, said fluid pressure meansembodying a piston and a cylinder element, means whereby the grippingmeans will be responsive in its operation to the operation of one 1 30of the parts of the cushion, means embodying pump mechanism responsivein its operation to the relative movement of the cushion elements forsupplying fluid between the cushion elements, and means operating tomaintain aI substantially unvarying pressure in the said cushion.

26. The combination of a sheet metal shaping member, means coperatingwith said member for shaping the material and embodying gripping meansfor the material, a freely detachable and self-contained fluid pressuremeans for maintaining a substantially lunvaryi'ng pressure on thegripping means during the operation of shaping the material, said fluidpressure means em"- bodying a piston and a cylinder element, meanswhereby the gripping means will be responsive in its operation to theoperation of one of the parts of the cushion, means embodyingmechanismresponsive in its operation to the relative movement of thecushion elements for supplying fluid between the cushion elements, andmeans operating to maintain a substantially unvarying pressure in thesaid cushion, the said fluid supplying mechanism receiving its supplyfrom the atmosphere.

27. The combination of a sheet metal shaping member, means coperatingwith said member for shaping the material and embodying gripping meansfor the material,

a freely detachable and self-contained fluid pressure means formaintaining a substantially unvarying pressure on the gripping meansduring the operation of shaping the material, said fluid pressure meansembodying a piston and a cylinder element, means whereby the grippingmeans will be responsive in its operation to the operation of one of theparts of the cushion, and means embodying pump mechanism responsive inits operation to the relative movement of the cushion elements forsupplying fluid between the cushion elements, the last recited meansembodying mechanism whereby the operative stroke of the pump mechanismmay be varied with relation to the said relative movement of the cushionelements.

28. A self-contained freely attachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable cushion elements, means for anchoring one of thecushion elements, mechanism to the operation of which the other cushionelement is responsive to cause a relative movement of the cushionelements, pump mechanism for supplying fluid between the cushionelements, said pump mechanism embodying a cylinder and piston, the saidcylinder and piston being one connected. -with the anchored cushionelement, and the other having an operative connection withthe firstrecited mechanism.

2 9. A self-contained freely attachable and termined pressure in thecushion.

detachable fluid pressure cushion for sheet metal die machines, saidcushion embodying opposed relatively movable cushion elements,

.means for anchoring one of the cushion elements, mechanism to theoperation of which the lother cushion element is responsive to cause arelative movement of the cushion elements, pump mechanism for supplyingfluid between the cushion elements, saidl pump mechanism embodying acylinder and piston, the said cylinder and piston being one connectedwith the anchored cushion element, and the other having an adjustable.operative connection with the first recited mechanism whereby theoperative movement of the pump mechanism with respect to the relativemovement of the cushion elements may be varied.

30. A self-contained freely attachable and detachable fluid pressurecushion for sheet metal die machines, said cushion embodying opposedrelatively movable cushion elements, means for anchoring one of thecushion elements, mechanism `to the operation of whichA 3l. Aself-contained freely attachable and detachable fluid pressure cushionfor sheet metal die machines, said cushion embodying opposed relativelymovable cushion elements,

Ameans for anchoring one of the cushion elements, mechanism to theoperation of which the other cushion-element is responsive to cause arelative movement of the cushion elements, pump mechanism for supplyingHuid between the cushion elements, said pump mechanism embodying acylinder and piston, the said cylinderv and piston being one connectedwith the anchored cushion element, and the other having an operativecon' nection with the first recited mechanism, the said pump mechanismreceiving its supply from the atmosphere.

32. A self contained freely attachable andY detachable fluid pressurelcushion for sheet metal die machines, said cushion embodying a cylinderand piston movable relatively one A with relation to the other, meansfor anchor- 4ing one of the parts of the cushion, a pump structurecarried with the cushion and adapted to supply fluid to the cushion, bythe relative; movement of the cushion elements, and means formaintaining a prede- 33. A self-contained freely attachableanddetachable fluid pressure cushion for sheet metal die machines, saidcushion embodying detachable fluid pressure cushion for sheet a cylinderand piston elements relatively metal die machines, said cushionembodying movable, means for anchoring one of the eleacylinder andpiston, means for anchoring ments, a pump mechanism responsive in itsone of the parts of the cushion, and apump l5 5 operation .to therelative movement of the structure adapted to supply fluid to thecushcushion elements, said pump mechanism opion, said pump beingoperable by the relative erating to supply Huid tothe cushion, andmovement of the cushion elements. i means operating. automatically tomaintain a In testimony whereof I have signed my substantially unvaryingpressure in the name to this specication on this 2nd day of 2o 10cushion.V May, A. D. 1918.

34. A self contained freely attachable and DAVID STRAND.

